The present invention relates to an apparatus for dredging up mineral resources, for instance, agglomerate manganese and the like scattered over the seabed.
In this kind of apparatus it is conventional to provide an endless rope fitted with a number of buckets at an equidistance to be conveyed downward to the seabed from a working barge floating on the sea level. The endless rope is pulled up by means of pulleys mounted on the barge to obtain ores gathered up in said buckets, then said buckets are once more glided down to the seabed for circulating said endless rope between the upper deck of the barge and the seabed so as to perform continuous gathering of submarine ores. In the foregoing apparatus, each of said pulleys is provided at the outer periphery thereof with grooved portions for engagement with said bucket, and the position for fitting said bucket on the endless rope has generally been adjusted to engage the bucket within the grooved portion satisfactorily. However, sometimes the endless rope becomes swollen and somewhat elongated in the sea-water. In some cases, the endless rope may cause slipping on the pulley, so that even though it has previously been adjusted so that the bucket should be engaged within the grooved portion of the pulley. As the operation time elapses, the bucket does not engaged successfully within the grooved portion of the pulley, thereby troubles such as fracture of buckets and the like have frequently taken place.
The present invention is aimed at to solve the above-mentioned problems occurring in conventional apparatus as well as to provide an apparatus which absolutely dispenses with the foregoing adjustment of positions for fixing brackets on the endless rope and is able operate safely and reliably at all times in spite of later troubles such as swelling of ropes by the sea water or slipping of ropes on the pulleys.